Cruciate ligament tear
Causes, symptoms and treatment
When it comes to movement – getting from A to B – the knee joints are the body’s lynchpin. Without knee joints, movement quite literally comes to a standstill. You need your knees not only to perform everyday activities but also for virtually all types of exercise and contact sports.
Muscles and ligaments play an important role in helping your joints do their job. In your knees, your cruciate ligaments play the lead role. If a cruciate ligament tears, it can no longer provide support – which can lead to a whole string of very unpleasant symptoms. Read on to find out more. We’ll also take a closer look at the causes of cruciate ligament tears and how they can be treated.
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What is a cruciate ligament?
Four ligaments connect your thigh bone (femur) to your lower leg bone (tibia). They include the two collateral ligaments that stabilise the inner and outer sides of your knee joint and the posterior and anterior cruciate ligaments located inside your knee. Your cruciate ligaments are crossed like the letter X and run diagonally through the cavity of the knee joint. Cruciate means cross-shaped, which is how they got their name.
What job do cruciate ligaments do?
Your cruciate ligaments serve as central stabilisers. They centre the articular surfaces of the knee joint and keep your knee in position at all times, whether at rest or with force or strain acting on it. Your cruciate ligaments support and guide your knee during flexion, at which point they are tensed. During knee extension, the collateral ligaments take over and are tensed. In this way, your ligaments control your movements and also set physiological limits to your range of motion. They protect your knee from sprains and keep it stable even when the surrounding muscles are not even tensed yet. Ligaments are able to provide natural, “passive” protection because they are not as elastic as muscles, which means they always offer a basic level of stability.
The anterior cruciate ligament (ACL) prevents the femur from slipping forwards over the tibia (this is known as the “anterior drawer”). The posterior cruciate ligament (PCL) prevents the tibia from slipping backwards under the femur (this is known as the “posterior drawer”).
What is a cruciate ligament tear?
A cruciate ligament tear in the knee – also known as a cruciate ligament rupture – is a complete tear of one or both cruciate ligaments. If a ligament is not completely torn, this is called a partial tear or rupture to a cruciate ligament. The anterior cruciate ligament in the knee joint is affected in a majority of cases, because the ACL is typically subjected to a higher level of stress in many accident situations. The posterior cruciate ligament only ruptures in about ten per cent of all cases.
When the anterior cruciate ligament ruptures, it can no longer prevent the femur from slipping forwards over the tibia. A ruptured PCL can no longer prevent the tibia from slipping backwards under the femur. As long as the medial and lateral ligaments are intact, your knee joint will still have a measure of lateral stability.
Statistically speaking, a cruciate ligament rupture occurs every five to six minutes in Germany. That adds up to some 100,000 cases per year. Eighty percent of these injuries occur during sports.
How can you rupture a cruciate ligament?
As ligaments are not particularly elastic, they can easily be overstretched if placed under too much strain. A cruciate ligament will generally tear if it is strained beyond its maximum tearing strength. There are various situations where this can happen. Most tears are caused by traffic accidents or sustained in contact sports or sports with a lot of movement. Sports that involve sudden changes of direction or speed have a higher risk factor. A cruciate ligament can also tear if it is twisted, sprained or hyperextended. This can happen due to a fall, collision or impact. Classic scenarios include hitting your knee on the dashboard in a car accident, battling for a ball in sports or landing after a jump. It can also happen if you fall when skiing and your ski does not release automatically, in which case the leverage effect can twist your knee. And the list goes on.
However, cruciate ligament tears can also occur in numerous everyday situations. All it takes is one wrong step – twisting your knee, slipping on the stairs, or falling off a ladder or chair when you’re doing DIY or hanging a picture is often enough to overextend a cruciate ligament and cause it to tear partially or completely.
What are the symptoms of a cruciate ligament tear?
In most cases, the symptoms of a cruciate ligament tear are very clear. They include pain, swelling and haematoma around the knee joint. You will no longer be able to extend or flex your knee fully. Some people don’t realise immediately that they’ve torn their cruciate ligament. It’s not until they try walking or bearing weight on the leg that their knee feels unstable and “wobbly”. The slightest pressure on the joint will then suffice to make the knee buckle and give way.
Many people report hearing a clear snapping sound and/or a crackle or a pop in the moment when the accident occurs. This is followed by acute and intense pain inside the knee. Another of the first symptoms can be a feeling of something tearing or moving suddenly inside the knee joint. Over the next few hours, the knee swells up. This, in turn, can result in throbbing pain caused by steady expansion of the joint capsule.
In many cases, the acute pain will subside relatively quickly if you rest, but will return as soon as you use the leg again. Blood vessels around the joint are often damaged during the injury as well. A haematoma can then develop, restricting the joint’s range of motion even further.
How can a cruciate ligament tear be treated?
It’s important to find suitable treatment that stabilises the knee and prevents further wear and tear to the joint (arthrosis of the knee). Experts are in agreement here on these aspects. The excessive range of motion in the knee joint following a cruciate ligament tear can be a direct cause of increased degeneration. However, experts have different opinions on the best course of treatment for this.
Some medical professionals believe that surgery is always the best option. In surgery, an orthopaedic doctor will either sew the ruptured cruciate ligament back together or graft in tissue from one of your thigh tendons in a procedure known as cruciate ligament reconstruction.
Other medical professionals do not consider an operation essential in all cases. Depending on the type of tear, they believe a torn ACL can heal with conservative treatment in many cases. This may be the case, for example, if the synovial sheath (a stretchy membrane around the cruciate ligaments) has not been destroyed completely and is able to hold the ends of the torn ligaments close together.
There are also many cases where special exercises to increase muscle strength can stabilise the joint enough to cope with the stress of sports, work and everyday life. If the knee joint is subjected to excessive strain, however, muscles may not provide enough stability on their own to compensate for a missing cruciate ligament. In general, operations on sporty and young people are more common compared to older patients.
Conservative treatment generally involves the use of a rigid knee orthosis that is worn for around six weeks and restricts the knee’s range of motion in a targeted manner. This prevents you from straining your knee or moving it improperly, both of which can put the success of your treatment at risk. A stabilising brace may also be used following cruciate ligament surgery.
How long does it take to heal?
Cruciate ligament tears always take several months to heal. If surgery is performed, this normally takes place two to four weeks after the rupture occurs. Until then, a suitable orthosis is used to stabilise the knee. Orthoses are also used after surgery. Patients will also need around four months of rehabilitation for the graft to heal properly and provide long-term stability. During this time, the body transforms the grafted tendon into a ligament. With conservative treatment, on the other hand, rehabilitation begins as soon as the injury has subsided. This can also take several weeks. So at the end of the day, both forms of treatment take a similar length of time. Rehabilitation therapy will primarily start with physiotherapy that moves the knee passively and focuses on building up muscle and doing coordination exercises.
The right exercises make all the difference
Professor Wolf Petersen, senior consultant in the orthopaedic and trauma surgery clinic in Berlin’s Martin Luther Hospital, is very clear about one thing: surgery can succeed only in combination with aftercare. In order to return to normal life, physiotherapy is not the only important factor. You will also need to play an active role yourself in the recovery process. Doing the right exercises at home makes all the difference to the success of your treatment and helps improve your symptoms.
This is exactly where the Genu Move exercise programme comes in. Developed by doctors, this programme covers a wide range of exercises designed for patients who are recovering from an ACL tear. The exercises support aftercare and are ideal for building up muscle strength. This enables you to actively contribute to your rehabilitation at home and increase the load-bearing capacity, mobility, strength and coordination of the affected leg.
